The invention further relates to a process for producing an assembled shaft, especially a crankshaft, transmission shaft or camshaft, in which sleeve members are inserted into tubular members and expanded, thereafter remaining permanently deformed. The tubular members abut each other and/or are inserted into each other and/or drive elements or bearing sleeves are slid on to the tubular members. The expansion of the sleeves takes place for achieving a forcelocking connection between the sleeve elements and the abutting tubular members or between the tubular members inserted into each other or between the bearing sleeves and the tubular members.
There are prior art assembled shafts which, because of their reduced mass, have advantages as compared to solid forged or cast shafts, and also as compared to hollow cast shafts.
Several different processes for producing the abovementioned shafts are known and operate with pressure agent probes provided with seals, with the outer diameter of the probes essentially corresponding to the inner diameter of the sleeves. The seals, which are subjected to pressures of several thousand bar, suffer from considerable wear during the application of pressure and also during the insertion and withdrawal of the probe so that they have to be replaced at regular intervals. Because the seals, due to their short service life, have a tendency to fail unexpectedly, the shaft in the process of being produced is destroyed.